Agitating mixer



June 23, 1936 F. WHIPPERMAN AGITYA'YIING MIXER I Original Filed Aug. 25,1934 0 E WE w HG m Patented June 23, 1936 UNITED STATES PATENT OFFICEDivided and this application March 23, 1935 Serial No. 12,710

1 Claim.

This invention has to do with the art of mixing machines in general andparticularly with agitating mixers for drying, heating and mixinggranular fuel material and the like in the method of making fuel-blocksdescribed in my application for patent of August 23, 1934, Serial Number741,073, of which this application is a division.

Briefly the above mentioned method of making fuel-blocks consists in thedrying and heating of granular fuel material such as coal and cokescreenings and fines and the like by pocketing therein hot combustionproducts from a suitable source of supply, mixing with the heated anddried fuel material molten asphaltic binder and then blocking the hotmixed material.

To satisfactorily prepare the granular fuel material for blockingsubstantially all of the moisture contained therein must be driventherefrom and the material heated to a suitable temperature for mixingwith the molten binder.

In preparing granular fuel material for blocking in the making offuel-blocks great diificulty has been experienced in drying and heatingsaid material particularly when the moisture content thereof is high asin certain lignites wherein often as much as forty or fifty percent ofmoisture may be present. Economical and efficient carrying out of anymethod of making fuel-blocks requires the rapid treatment of thegranular fuel material to quickly dry and heat same to reduce to aminimum the consumption of fuel required for said drying and heating ofsaid material.

It is therefore an object of my invention to provide an agitating mixerfor thoroughly drying the fuel particles, heating the same suflicientlyto insure the uniform coating of the particles with melted binder, andeliminating from the product water and certain volatiles and deleteriousingredients such as sulphur, while utilizing heating values of sucheliminated constitutents to furnish a portion of the heat required forthe preparing Figure 1 is a plan view of my invention with the i 7 coverremoved to show' the interior of the machine.

Figure 2 is a section through the mixer and operatively associatedfurnace.

Figure 3 is a cross-section of the mixer blade.

The drying, heating, expulsion of volatile and vaporous matter from thegranular fuel material and the mixing of the binder with saidfuelmaterial may be all effected in my agitating mixer, the preferredembodiment of which is represented in the drawing which is now moreparticularly referred to. Reference numeral I6 indicates a cylindricalbody closed at the ends byend members I! which extend downwardly and aresecured to longitudinal base-members l8 adapted to be bolted orotherwise secured to a floor or base. The body I6 is provided with acentral opening l9 in the top thereof through which granular fuelmaterialto be treated and prepared for'blocking is admitted from asupply hopper 20. Doors 2| are provided at the lower end of the hopper2D'and said doors may be opened to permit fuel material to pass from thehopper into the cylindrical body. The doors 2| are normally closed toretain the next batch of fuel material in said hopper until the previousbatch has been treated in the agitating mixer and discharged therefromand the mixer is ready to receive the succeeding batch of material. Anoulet '22 is provided in the lower body wall through which treated fuelmaterial is dis-' charged into a receiving hopper 29 of a blockingmachine, not shown, upon the opening of a door 24 which normally closessaid outlet 22.

' Agitation of materials in the cylindrical body is effected by aplurality of part-helical blades 25 mounted on supporting arms 26secured to a square shaft 21 rotatably mounted centrally of thecylindrical body and having the ends thereof mounted in heat-resistingbearings 28 spaced outwardly of the end members I! to position saidbearings away from the heat within the body. The blades 25 extendinwardly from their respective ends substantially two-thirds the lengthof the cylindrical body thus theirrespective spheres of agitation withinthe'body overlap causing the fuel material therein to be .worked'towardthe longitudinal center of the cylindrical body with a rotating,oscillating movement thereby more thoroughly agitating the fuelmaterial. Each blade is provided with a flange 29 extending outwardlyand slightly downwardly from the lower edge thereof, said blade andflange forming an obtuse angle in cross-section as shown in Fig- 1 Itshould be noted that the flanges extend outwardly of the blades in thedirection of rotation of said blades.

In operation the blades enter material in the body at an angle and plowthrough it much as would the mold-board of a plow. The material isscooped up by the blades and a substantial portion thereof retained onthe flanges until the respective portions of the flanges pass the uppervertical center of the cylindrical body where the downward inclinationthereof causes said retained material to drop therefrom as the bladesrotate thus forming a wall or barrier of thefalling material, saidmaterial, as it is dropped, being interposed between opening 32a;the-inlet for hot combustion products, and outlet 35.

Heat for drying and heating the batch of material in the mixer issupplied from a furnace 30 preferably positioned beneath the mixerthough it may be placed at the rear thereof or in any-othersuitableposition. In the preferred embodiment'the agitating mixer ismounted on the furnace as shown in Figure 2. Themixer body is providedwith the inlet 32aadapted to receive hot combustion products downwardlyinto said body-from a'flue 3! from said furnace, said flue having anoutlet 32 of reduced dimensions in register with said inlet'32a. Theflue has-a firebrick arch 33 at the top thereof that directs the heat;gases and flames downwardly-into the mixerand-is also provided with awall 34, transversely pointed at the top, said pointed topextending'into thearchway 'of the flue. The upper point'of the wall34-is higher than the'lower edge 35 of the arch of the flue therebyforming a baffle" to prevent the heat, gases and flames from the furnacefrom normally passing directly across the top portion of themixer andoutthe outlet'36 therein. The bottom or ash-pit doors of the furnace, notshown, are normally kept closed. A blower 31-deli-vers air intotheash-pit Sir-through an opening 39 in the furnace wall,

' w'herebyforced draft may be applied to the-furnace, andfthe volume ofair 'passing-through-said furnace effectively regulated. I

Coal screeningsand fines areconveyed-to and deposited'into the hopperwhy 'any' suitable means such as an elevator conveyor. Saidscreenings'and fines vary in size from fine dust to" about /9 inchpieces such as would pass through themesh' of a screen and certaindefinite amounts thereofare batched by weight or'oth'erwise and a'llowedto'pass from the hopper 20 into the mixer-by regulation of the 'doors 2l The material is then thoroughly agitated, rolled and tumbled in the"mixer and dropped from the flanges:29of"th'e blades 25. The'heat andgases from the furnaceare somewhat compressedas they passthroughithe'reduced outlet are: the flue and'as-theyleave the flue theyexpandin the mixer. Said heat and gases aredirected downwardly'by thearch of the flue directea'chother in the .ispocket'ing heat andigasesand passing the inlet lyinto the agitated mass of fuel material in thelower portion of the mixer and the material droppedfrom the blades 25cover and pocket said heat andgases. The blades then agitate the heatandgases and fuel material and thoroughly mix same" together.

[ -Inthis manner the material is dried and the wet gases and vapor fromthe material escape froin'tlfe'mass ofmaterial and pass out theoutlet36. The blades are diametrically opposed'to While the upper blade3221, the opposite blade i's'approaching said inlet.

During a brief interval after one blade has passed the inlet 322 and theopposite blade has not yet reached the outlet no barrier is presented tothe heat and other combustion-products entering the inlet and they willpass from the inlet, into the mixer, and leave through the outlet 36without being mixed with the material in the machine. A draft is therebycreated which clears the upper part of the mixer of all moist vapors andgases. The rising blade then passes the outlet 36 and drops materialfrom the flange, stopping the direct passage of heat and gas from theinlet across the upper portion of the body and out through outlet 36.Due to the blades not extending the entire length of the body of themachine there isaslight draft around the inner ends of the blades at alltimes to aid in the expulsion from the machine of moist vapors and gasesdriven from the material being treated.

It is found in practice that by supplying sufficient heat to the mixerby the burning of outside coal or other fuel to evaporate the moistureinthe granular fuel material in the machine and raising the temperaturethereof by pocketing said outsideheat in the material being treated,self or vdust of said material, and this self or internal heating of thefuel isthen carried on automatically until the proper temperature formixing of the material with the binder is reached. This burning ofvolatiles and dust within the machine effects a marked reduction in thetotal amount of fuel required to assure the drying and heating of thegranular fuel material to the desired temperature because of the directapplication to and generationof heat within the material itself. Also bythe described mode of operation, discharge of unburned volatiles anddust into the air is avoided, and there is no'liability or danger ofexplosions by accidental ignition of dust, or unburned volatiles,expelled from the granular fuel material by the heating thereof to thetemperatures desirable for mixing with binder material and for theblockingoperation. Ignition and burning of the material itself isprevented by the constant tumbling and agitation thereof by the bladesand the drying and heating is so controlled that the temperature of thematerial being treated may be raised in the mixer to any desired pointat which tively coated with a thin film of the binder, and

the'mixed material is then discharged from the machine into thereceiving hopper 23 of a blocking machine.

It is to be understood that the heating of the mass of granular materialand binder continues while the mixing thereof is effected to preventcooling thereof, during the mixing operation, to a temperature belowwhich satisfactory blocking could be effected.

My agitating mixer is relatively simple and inexpensive to manufacture,and the cost of treating and mixing granular fuel material with asuitable binder with my mixer, proportional to the output thereof, isvery low, so that said treatment may be effected economically, whileincreasing the value of the coal or coke screenings and fines toequivalence with that of the respective unbroken fuel.

It is, of course, to be understood that the invention may be constructedin other manners and the parts associated in other relations, and,therefore, I do not desire to be limited in any manner except as setforth in the claim hereunto appended.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

An agitating mixer for treating granular fuel material such as coal andcoke screenings and fines and the like in the production of fuel-blocks,comprising a horizontal, substantially cylindrical body having an inletfor hot combustion products adjacent the top of the body and on one sideof the vertical center thereof adapted to admit hot combustion productsdownwardly into said body, and an outlet for vapors and gases adjacentthe top of the body and on the opposite side of the vertical center fromthe inlet, and a plurality of blades extending longitudinally of thebody and 5 said material toward the inlet and downwardly 10 to the lowerportion of the body, to pocket hot combustion products, admitted throughthe inlet, in the granular fuel material, said dropped materialextending transversely of the current of hot combustion productsadmitted through said inlet. 15

FRANK WI-HPPERMAN.

